Hlp with alphablend

[berrick]

Hi everyone,

I'm learning VB and hope you can help?

I can use alphablend to produce the result i want which i display in a picture box and everything looks great. The problem is that if i then try and reference the picture i have just produced i dont display the picture?

For example

if objItem.Lockout = False then

Set msflexgrid.CellPicture = Picture2 'picturebox where alphablend image displayed

End If

I guess i'm doing something silly but i dont know what

[Hack]

Moved from the CodeBank

[Fazi]

Hai berrick

not sure exactly what your problem is weather with displaying alphablended picture or with your flexgrid. Here is an Alphablended picture discussion thread: http://www.vbforums.com/showthread.php?t=463045

[berrick]

Thanks for the reply Fazi,

I'm trying to do something more basic than shown in those threads....
Here is the code

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" ( _
lpvDest As Any, lpvSource As Any, ByVal cbCopy As Long)

Private Type BLENDFUNCTION
BlendOp As Byte
BlendFlags As Byte
SourceConstantAlpha As Byte
AlphaFormat As Byte
End Type
' BlendOp:
Private Const AC_SRC_OVER = &H0
' AlphaFormat:
Private Const AC_SRC_ALPHA = &H1

Private Declare Function AlphaBlend Lib "MSIMG32.dll" ( _
ByVal hdcDest As Long, _
ByVal nXOriginDest As Long, _
ByVal nYOriginDest As Long, _
ByVal nWidthDest As Long, _
ByVal nHeightDest As Long, _
ByVal hdcSrc As Long, _
ByVal nXOriginSrc As Long, _
ByVal nYOriginSrc As Long, _
ByVal nWidthSrc As Long, _
ByVal nHeightSrc As Long, _
ByVal lBlendFunction As Long) As Long

Private Sub Form_Paint()

Dim lBlend As Long
Dim bf As BLENDFUNCTION

bf.BlendOp = AC_SRC_OVER
bf.BlendFlags = 0
bf.SourceConstantAlpha = 255
bf.AlphaFormat = AC_SRC_ALPHA
CopyMemory lBlend, bf, 4

AlphaBlend Picture3.hDC, 0, 0, _
Picture3.ScaleWidth \ Screen.TwipsPerPixelX, _
Picture3.ScaleHeight \ Screen.TwipsPerPixelY, _
Picture1.hDC, 0, 0, _
Picture1.ScaleWidth \ Screen.TwipsPerPixelX, _
Picture1.ScaleHeight \ Screen.TwipsPerPixelY, _
lBlend
Picture2.Picture = Picture3.Picture
End Sub

Similar to other code i have seen in other threads on this site.
Anyway, as i have stated all appears to work, i have picturebox1 loaded with a picture with plenty of black on the alpha channel this is combined with and displayed in picturebox3 which before this code runs has a purple fill. Therefore picturebox3 displays a purple backgroound and the picture from picturebox1 without the black.

If i then try to display the picture in picturebox3 in picturebox2 i get a picturebox with a gray fill nothing else??


Hope this clearifies my problem.

Hoping someone can point out what i'm doing wrong

[berrick]

Bump.

Anyone able to offer a posible answer??